Madadian Motor Cars

Madadian Multi-Squillionaire Sheik Ratelunroll has bought four prestige cars from the Madadian Motor Company (MMC) - The Silver Dream, The Golden Pleasure, The Devine Lightning, and a The Rusting Bucket, - as presents for his sons' birthdays, all of which are next week (strange things like this happen in Madadia all the time). Given the following information, what will each son get?

1, Derek will not get The Golden Pleasure unless Berrick gets The Silver Dream and Eric gets The Rusting Bucket.

2, Berrick will not get The Rusting Bucket unless Merick gets The Devine Lightning and Derek gets The Silver Dream.

3, Eric will not get The Devine Lightning unless Derek gets The Golden Pleasure and Berrick gets The Silver Dream.

4, Derek will not get The Silver Dream unless Merick gets The Devine Lightning and Eric gets The Rusting Bucket.

5, Berrick will not get The Silver Dream unless Derek gets The Devine Lightning and Eric gets The Rusting Bucket.

6, Derek will not get The Devine Lightning unless Berrick gets The Golden Pleasure and Merick gets The Silver Dream.

7, Merick will not get The Devine Lightning unless Berrick gets The Golden Pleasure and Derek gets The Rusting Bucket.

8, Derek will not get The Rusting Bucket unless Berrick gets The Devine Lightning and Eric gets The Golden Pleasure.

9, Merick will not get The Silver Dream unless Eric gets The Golden Pleasure.

Answer

Starting with the simplest requirement, #9, assume that Eric does in fact get The Golden Pleasure, then Merick gets The Silver Dream. This leaves The Rusting Bucket and The Devine Lightning for Berrick and Derek. Going to rule #8, Eric already has The Golden Pleasure, so if Berrick gets The Devine Lightning, then Derek can have The Rusting Bucket. This gives us the following that complies with rules 8 & 9: